MCQ on First Law of Motion

Newton’s first law asserts that if a body is at rest or moving in a straight path at a constant speed, it will remain at rest or continue to move in a straight line at a constant speed until acted upon by a force. In fact, in classical Newtonian mechanics, there is no significant difference between rest and uniform motion in a straight line; they can be considered the same state of motion seen by two observers, one moving at the same speed as the particle and the other moving at a constant velocity with respect to the particle. The law of inertia is the name given to this concept.

1. What causes a body to move after it has been in a condition of rest?

a) Force
b) Displacement
c) Speed
d) Velocity

Answer: Correct option will be: (a) Force

Reason: The first law of motion asserts that unless and until an external force act upon a body, it will remain in motion or at rest. As a result, the answer is force. The law of inertia is another name for this.

2. When a moving bus comes to a stop, passengers feel a jolt. This is the consequence of ____

a) Inertia of motion
b) Inertia of turning
c) Inertia of acceleration
d) Inertia of rest

Answer: Correct option will be: (a) Inertia of motion.

Reason: When the bus comes to a stop, the passengers feel a jerk. This is due to the fact that while the bus was in motion, the passengers were also moving. As a result, they were experiencing motion inertia) When the bus comes to a complete stop, its inertia shifts from motion to rest. People’s inertia, on the other hand, is still that of motion. As a result, they feel a jerk.

3. A bus that is travelling straight makes an abrupt right turn. What will happen to those who are on board the bus?

a) They will lean rightwards
b) they will lean leftwards
c) they will remain stationary
d) they will begin jumping

Answer: Correct option will be: (b) they will lean leftwards

Reason: The inertia of the bus changes when it makes a quick right turn. However, the passengers’ inertia remains in the direction of travel. As a result, they’ll be moving to the left.

4. When a train makes a turn, why don’t we notice any leaning?

a) As Because the train is powerful
b) the turning radius is large
c) the train does not turn
d) the driver is intelligent.

Answer: Correct option will be: (b) the turning radius is large

Reason: When comparing to the turning radius of ordinary vehicles, the train has a considerable turning radius. As a result, there are no sharp or abrupt turns. As a result, there is no leaning for the passengers.

5. What will be the mass of an item that accelerates at a rate of 2.6 m/s with a force of 90 N?

a) 44.6 kg
b) 34.6kg
c) 93.6 kg
d) 64.6 kg

Answer: Correct option will be: (b) 34.6 kg
Calculation: To calculate the mass of the object we will use the formula:
F=ma, Here F is the force, m is the mass and a is the acceleration.
🡺90=m(2.6)
🡺m=34.6 kg

6 . The first law of Newton is also called as:

a) Law of rotation
b) Law of displacement.
c) Law of momentum
d) None of the mentioned

Answer: Correct option will be: (d) None of the mentioned)

Reason: The law of inertia is another name for Newton’s first law. ‘Unless an unbalanced force acts upon it, an object will remain at rest and an item in motion stays in the same direction and speed)’

7. If the force applied to an object is doubled and the mass is cut in half, the object’s mass will be cut in half. What would be the accelerations’ ratio?

a) 1:2
b) 2:1
c) 1:4
d) 4:1

Answer: Correct option will be: (c) 1:4

8. Dirt may be cleaned from a rug by violently shaking it for a period of time. This process is based on:

a) Newton’s second law of motion
b) Newton’s third law of motion
c) Newton’s first law of motion
d) Both a and b

Answer: Correct option will be: (c) Newton’s first law of motion

Reason: When we hit the blanket, the material of the blanket pushes ahead with the stick. However, because the dust particles were at rest, they will remain at rest in their current location. As a result, dust particles will split first from blanket and drop to the ground as a result of gravity.

9. A cricket fielder throws his hands backwards after collecting a ball. This is described by the principle behind it.

a) Newton’s second law of motion
b) Newton’s third law of motion
c) Newton’s first law of motion
d) Law of inertia

Answer: Correct option will be: (a) Newton’s second law of motion.

Reason: When the ball is caught, its velocity is abruptly reduced to zero and it ceases to move. The impact of momentum on the fielder’s hands will be significant, and his hands may be injured as a result. Swinging his hands backwards lengthens the time it takes for the ball’s velocity to fall to zero. This lessens the force pressing on the fielder’s hand by lowering the rate of change of momentum. This reduces the risk of injury to the hands. Newton’s second law of motion explains the relationship in between rate of change of momentum and the force applied)

10. A body’s linear momentum changes at a rate proportional to the____ applied on it.

a) Impulse
b) Force
c) Kinetic energy
d) Torque

Answer: Correct option will be: (b) Force.

11. Ranveer pulled a tablecloth off a table without knocking over the plates. This is because of:

a) Inertia
b) Impulse
c) Force
d) Momentum

Answer: Correct option will be: (a) Inertia)

12. The body will move with___, if the supplied force is constant.

a) Consistent speed
b) Maintain a constant speed
c) A constant rate of acceleration
d) Constant forward movement

Answer: Correct option will be: (c) a constant rate of acceleration.